Depot Maintenance:

Executed Workload and Maintenance Operations at DOD Depots

GAO-17-82R: Published: Feb 3, 2017. Publicly Released: Feb 3, 2017.

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Zina Dache Merritt
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What GAO Found

From fiscal year 2012 through 2015, the workload executed across the military services’ depots fluctuated. For all four military services, the greatest decrease in depot maintenance workload occurred in fiscal year 2013, which officials attributed to sequestration. Specifically, in response to reduced funding levels, some military services deferred depot maintenance that had been planned for fiscal year 2013 to future years. The number of workload hours executed at Army and Marine Corps depots has generally declined over this time period as a result of a decrease in ground combat operations for the Army and Marine Corps, and is expected to decrease in the future, according to Army and Marine Corps officials. Workload hours executed at Air Force depots, according to Air Force officials, has fluctuated over this time period and is expected to increase in the future, as depots begin repairs on new systems, such as the F-35 and KC-46. Additionally, workload hours executed at Navy depots has generally increased over this time period and is expected to continue to rise, which the Navy attributed to reducing maintenance backlogs that have accumulated from over a decade of increased operations tempo.

Why GAO Did This Study

In order to meet national security goals, the Department of Defense (DOD) uses a combination of military depots—public-sector facilities that are government-owned and government-operated—and private-sector contractors, to maintain, overhaul, and repair its military weapon systems. The military services operate 17 government-owned facilities that primarily perform depot-level maintenance on a wide range of vehicles and other military assets, including helicopters, combat vehicles, ships, aircraft, engines, and software. According to DOD, in fiscal year 2015 there were approximately 45,000 civilian personnel at the depots that perform maintenance and 30,000 other civilian non-maintainers—engineers, scientists, analysts, and supply specialists—essential to depot maintenance production.

Senate Report 114-49 and House Report 114-02 accompanying the National Defense Authorization Bill for Fiscal Year 2016 each included a provision for GAO to review DOD’s processes and management of core capability requirements at the military service depots. In November 2016, GAO issued Depot Maintenance: Improvements to DOD’s Biennial Core Report Could Better Inform Oversight and Funding Decisions, GAO-17-81 (Washington, D.C.: Nov. 28, 2016) that addressed the planning and execution of depot maintenance workloads to sustain core capability requirements. This report provides additional information by describing the executed maintenance workload at the military services’ depots from fiscal year 2012 through 2015 and provides detailed information for each of the 17 depots, on executed workload, personnel, capital investments, process improvements, and public-private partnerships.

To assess DOD’s processes and management of core capability requirements at the military service depots, GAO collected information on the military services’ processes for managing, planning, and executing depot maintenance workloads by contacting officials from each of the military services; collecting data on workload, personnel, and capital investment for each military depot; conducting site visits to nine depots; and collecting information through questionnaires from all 17 depots.

For more information, contact Zina Merritt at (202) 512-5257 or

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